Machine for fluting twist-drill blanks.



O. S. BICKFORD.

MACHINE FOR FL UTlNG TWIST DRILL BLANK S. APPLICATION FILED MAR. I2. 1911.

1,274,502. Patented Aug. 6, 1918.

3 SHEETSSHEET l.

lid-9 if; 2; F? 07722 0. S. BICKFORD.

MACHINE FOR FLUTING TWIST DRILL BLANKS.

APPLICATION FILED MAR. I2. I9II.

1 ,274, 502. I Patented Aug. 0, 19m

3 SHEETS-SHEET 2,

aw/2507 I 4'0.

0. S. BICKFORD.

MACHINE FOR FLUTING TWIST DRILL BLANKS.

APPLICATION FILED MAR. I2. I9II.

1 ,274, 502. Patented Aug. 6, ma

3 SHEETS-SHEET 3.

MACHINE FOR FLUTING TWIST-DRILL BLANKS.

Application filed March 12, 1917.

To all whom it may concern:

Be it known that I, ORAMEL S. Bicnronn, a citizen of the United States of :unerica, residing in Greenfield, in the county of Franklin and State of h tassachusetts, have invented certain new and useful. Improvements in Machines for Fluting Twist-Drill Blanks, of which the following is a specification.

This invention relates to improvements in machines for tinting twist drill blanks. The invention, broadly, Comprises mechanism for feeding the blank forward toward the cutter or tinting member at practically a uniform rate of linear travel, also at varying rates of rotation of the blank during the cutting or tinting operation, whereby the pitch or lead of the tinting grooves is varied from the cutting end of the drill to ward its shank.

An object of the invention is to provide means 'for automatically reversing the blank carrying carriage at the extreme ends of its travel, said means including mechanism tor varying the rate of travel of the carriage. That is to say, during a part of the forward movement the carriage moves slowly and during the balance of the cycle ot operation or movement of the carriage it moves faster.

A further object ot the invention is to provide means for automatically rotating the blank through 180 degrees after the first tlute or groove has been cut. whereby when the cutter begins to operate again, it will cut or tlute the blank on the opposite side.

A turthcr object of the invention is to provide means for automatically disengaging the cutter from the blank after the spiral or tluted grooves have been completed. Further objects and nature of the invention will appear in the body of the specitication and will be particularly pointed out in the claims.

ltet'erring to the drawings:

Figure 'l is a top plan view showing the drill blank held in place during the cutling operation. also'the means For impart.- ing a rotalive movement to the blank simultaneously with the torward movement thereof. and the trip mechanism t'or automali cally disengaging the relative mechanism from the spindle carrying the drill blank:

Fig. '3 is a side clevational view of Fig. 1. showing the means for vertically adjusting Specification of Letters Patent.

Patented Aug. 6, 1918.

Serial No. 154,099.

the table also the mechanism which imparts a rotative movement to the blank, and the cam device by means of which the lead or pitch of the groove being cut in the blank is varied;

Fig. 3 is a vertical sectional view on the line 33 of Fig. .1, showing the mechanism by means of which the head stock is operated and the mechanism by means of which the angular elevation of the same is varied, also the mechanism by means of which the driving mechanism for the head stock is automatically disengaged at the end of the cutting operation;

Fig. 4 is a detail side elevational view of the automatic means For varying the lead. or pitch of the groove in the blank as it is being cut;

Fig. 5 is a detailed view of the inclined groove constructed that is attached to the lever mechanism for lowering the carriage to disengage a cutter at the end of the stroke or travel;

Fig. (3 is a view of the index device by means of which the drill blank is permitted to rotate about its axis during the cutting operation when the clutch is iuengagement:

Fig. 7 is a detail view showing the two positions of the drill during the cutting operation and after the same is completed and moved a 'a v from the cutter;

Fig. 8 is a side elevational view of the opposite side of the machine from that shown in Fig. 2 and illustrating the mechanism tor moving the carriage back and torth. also the trip mechanism for automatically changing the speed of the movement of the carriage during its travel. also showing the train of gearing between the driving pulleys and the worm sha'tt which extends longitndinally ot the machine from which the various operations (it the machine are driven.

Fig. 9 is a detail view of the bushing through which the drill blank slides while beinrr cut;

Fig. 10 is a detail view of one end of the adjusting lever.

Referring to the drawings in detail The base portion of the machine is indicated at l and secured to this portion are the upright standards 2 which carry the cutter shaft 3 to which the cutter 4 is secured. Secured to the cutter shaft is the cone driving pulley 5 designed to he belted to any suit-- able source of motive power. 6 designates the train of interchangeable gearing which is interposed between the driving shaft 3 and the worm shaft 7. 8 and 9 are two beveled. gears which mesh with the idle bevel gear 10. The gear 10 is secured to a listed shaft or stud 11 which passes downward through the base portion of the machine as shown in Fig. 3. The worm shaft 7 is mounted in bearings which are mounted on the movable plate 12. This plate is adapted to be moved about the fixed stud 11 as a center for the purpose of varying the angular relation between the cutter spindle 3 and the axis of the drill blank. The plate 12 is clamped in rigid position by means of the bolt and nut construction shown at 13 and which moves in the slot 13. It should be mentioned that the axis of the stud or bolt 11 must necessarily pass upward and intersect the center or axial line of the cutter spindle 3. A movable head stock i l supports the drill blank. The bushing 15 (see Fig. 9) through which the drill blank,

indicated at 16, passes when the blank is being fluted or grooved is supported on an adjustable table 19. This blank is held in the chuck 17, the spindle of which passes.

through the bearing 18, which is also a part of 14, referred to later, which is mounted on the adjustable plate or table 19. designates the spindle which drives the chuck and on the inner end of which is loosely mounted a gear 21 having attached thereto a clutch plate 22. lnterengaging with this plate is another clutch plate These two plates are formed with two projections and recesses respectively which serve to cause the spindle 20 to be rotated about its axis simultaneously with the forward movement of the head stock 14. Spaced from the plate 23 is an integrally connected plate 24 and located between the plates 23 and 2% is the shift fork 25 which is secured to the rock shaft 26. Attached to the end of this shaft is the arm. 27 and pivotally attached to this arm is a pawl 28. This pawl is designed to engage at its lower end with a pin 29 which is carried by the ad-- justable plate 30 for the purpose of separating the clutch plates 22 and 23 when the head stock l l returns to its initial position toward the left. The plates 23 and 24: are slidably mounted on the spindle 20- which is driven by means of a key connection between the hub 24 and the spindle. To the end of the spindle 2G is secured a disk 81. lntei'pcsed between this disk and the slidable plates 23 and 2d and their integral hub ill is a coiled compression spring 32 the purpose of which is to normally hold the plates 22-and 23 together. Secured to the bearing block 18 .is a stud 33011 which is mounted spur gear 3 and connected to this gear is a bevel gear 35 which in turn meshes with the bevel gear 36 that is rotatably mounted on the stud 352, also secured the net/s ecs rod 40 carries a roller 42 or other device Y which is located in the groove as out the an- .gular shaped cam block 44c. The groove l3 intersects the groove 45.- The upper ends of the grooves l3 and l5 are shown in plan view in Fig. 1. The gear 86 is rotated as the head stock 14 is moved forward and backward by reason of the connection between the roller 42 and the groove 43 in the adjustable cam block ll, which rotation of the gear 36 is transmitted through the pinion 35, gear 34, and pinion 21 to the clutch plates 22 and 23 and spindle 20 which in turn rotates the drill blank 16 about its axis simultaneously with the movements of the head stock ll either forward or backward whereby a' spiral flute or groove is cut in the blank by the cutter on the forward movement of the blank.

lit should be stated that the block l l having the grooves 48 and 45 therein is adjustably secured to the fixed support 46 which is formed with graduations 4-7 on the curved edge 48 (see 1). This block is formed with a slot 49 to receive a clamping bolt 50 for the purpose of adjustably securing the cam block 44; in different positions of adjustment, The cam block ll is pivotally secured to the frame of the machine by means of the angle iron 51, the arms 51 and 52 of which being connected to the plate 46 by means of the bolts 53 and 54C. lt will, therefore, be seen that as the head stock 14.-

moves backward or forward carrying the plate 38 with it, that the gear 36, by reason of the slidable connection between roller 42, and the inclined groove 43 in the cam block 44- will be rotated on its pivotal stud 37, which in turn will, as previously stated. rotate the drill blank about its axis. The rate at which the gear is rotated will of course determine the lead or pitch of the flute or groove which is cut in the drill blank. This rate is determined by setting the cam block 4:4: in different positions oi adjustment with relation to the fixed block 4:6. The head stock is is mounted on a vertically adjustable table 19:, the forward end of this table is connected by means of aflink 55 to the i riddle point of a. lever 56 that is movable around the pin or stud 57 for adjusting the angular position. of the table 19 which determines the depth of ofthe drill blank. The forward end of the lever 56 is adjustable by means of the screw 58 and held in position by means of the graduated clamping not 59 shown in Fig. 2. The other of the lever 56 is automatically moved lit) hy means on inelinee slot construction shown at interposed between upright 12 or the machine and slide 62 is u spring til. Mounted in a transverse opening 63 in the lever 56 is a block M which block is formed with a semi-cylindrical projection 35. This block is ndjustnbly retained in place in the lever 56 by means of the two set screws (3-8 ilior varying the position of the block l t in the lever 56. The inclined slot 60 previously referred to intersects the slot 67. The slide 62 carries the roller which is held against the loco oi the can! 70 by moons of the spring 61. This cum is formed with n concentric surface 71' and a let-on and let olf portion 72 and 73, rospeetively. Located in the inclined slot (30 is a pin M which is attached to the slide 62 and is adapted to be moved up this incline by the cam wheel 70, whereby this end of the lever 56 will he moved downward and is for the purpose of gradually moving the drill blank downwardly from the cutter, as shown in Fig. 7 while the flute in the blank is being cut the desired depth and length during which time the hood stock 1st is moved to its forward position toward the right hand end of the machine.

The cam is operated :t'rom the cone driving' pulleys 5 through the bevel gears and 9 and 10 and the worm shalt 7. On this shetlt is formed the worm 75 which meshes with the worm gear 76 that in turn operates the cam. 70. This gear through the crank wheel 82 moves the head stock ital: forward and backward, the speed of rotation being automatically changed us will be described in connection with the construction shown in lg. 8, wherein the head stock 1 t is connt ed to a link 77 which in turn is connected to a: link 78 that is pivoted to the frame at Mounted in the opening S0 of this is a slide block Si which lolortc is nd i "iloly connected to tie ernnl: wheel The crank wheel is loculcd on the same shalt as the genr wheel 90 l 3) and is operable from the ,igeurs 89 end The extent travel of the hen-Ll stool; can, therefore he variiul by verying the position of the bloc; Si. in the open-- ing 80 ot' the link 78 and in the slot t of the crn'nl: wheel, The rrnnl; wl

)J is provided with the trip dogs 83 end also with slot 83 to receive the T u of the belt for :uljnstahly securing the i i the slot 8:) of the link l8. 'ilhe ")ldtftltl l dillerent positions nt hy in ens oi?" the'recesse 7 vs b these dogs l is mount d on or ill? which is piwted at .r 87 that controls 'id, as the cranlt wh "he pin 85 x ci'innected to n lever the point 853 and the the operation of the set oil ditleronthd ing and clutches in the or in: change the role of me off the k,

Ll-it from the high to the low speed and vice verso, whereby a slow speed forward can be given to the head stock i l and a quick rcturn on the reverse movement of the head stock. lt is to be understood that the construction of the dill'erontml gearing in the box 87, which is controlled by the levers 86 end 87 is a well known structure and does not form any part oi the present invention and is merely illustrative of the means employed to carry out a definite result, vim, to obtain a slow speed :lorwnrd and a test speed rearward. Secured to the shaft 88 is a pinion 89 {see Fig. 3) which meshes with the gear 90. The diameters oil. the gears 89 and 90 are in the ratio of two to one, respectively. Carried by the gear 90 is n pin 91 which pin is designed to en age the lever 92 and more the same away from the pin 93 which is mounted on the worm shnilt supporting box 7" in which is located worm shaft 7, this pin enters the recess 94: when the worm shuit 7 is elevated by hand. This shaft 7 drops aided by spring;- tension (not shown) and disenguges the gears 75 and 76 from each other when the pin 91 strikes the lever 92. This operation takes place when the flutes or grooves in the opposite sides of the drill here been completed end the moohine then comes to a stzuulst-ill as readily understood. The worm shalt 7 moves about the pivot 8 as teeth 75 and 76 are disen gagged when the pin 91 moves the lever 92 nwny'. After a new drill has been inserted the operator then raises the worm shaft 7 by menus oi the handle 05 and the machine is again set in motion as soon as the gears 75 and 76 mesh.

lhe operation as a whole may he described us follows: onsider u drill blank 16 to be inserted in und secured in the chuck 17'. The head stock, being in the position shown in Figs. l and 2, is moved forward toward the cutter -l through the connections between the cone pulley 5 and the head stock. the head stock it is moved forward through the link connections 77 and 78 the angular shaped cam block ll is simultaneously and automatically imparting o rotary movement to the drill blank which determines the pitch or lead ol" the flutes or Ln'oovos. lVhcn the cutter 'l commences the out the roller ($9 is at the bottom of the let oil portion Til ot' the cam wheel TO. As the roller (39 passes over the ewentric surface "(0' the lever 56 through the link 55 causes the table 19 to be graduully moved downwurd since the pin 74 on the slide (32 travels up the slightly inclined. slot (37 in the block (ll, and when the roller (39 puss s up the shoulder onto the concentric surface ll of the cam 70, the pin Tltravels quickly up the sharply inclined slot (50 ot the block e at which time the drill blank 16 is then completely drawn away from the cutter as drill remoy'ed and a new one inserted.

shown by the dotted line 16 in Fig. 7. During the time the roller 69 is passing over the concentric surface 71 of the cam the head stock 1 1 is moved to the end of its travel at the left hand end of the machine and forward again to its initial position shown in Figs. 1 and 2. The speed of this return movement is effected through the trip blocks 83 on the crank wheel 82 which engage the projection 85 on the lever 86 which is pivotally attached to the top of the differential gear case 87 at 85. 87 is a lever which controls the clutch and differential gears in the gear case 87. Meanwhile, during the last part of the movement of the head stockl to its rearward position and after the drill blankiis withdrawn from the bushing 15 the drill blank 16 is automatically held from being rotated since the clutch plates 22 and 23 are now separated after having been rotated to produce one groove or flute, during the cutting of one flute by means of the connection between the gear wheel 36 and the pinion 21 on the spindle 20. That is to say the pitch of the flute exfends through 180 from beginning to end. The clutch plates 22 and 23 are, during this last part of the return movement, disengaged by means of the trip finger engaging the pin 29. the end of its rearward travel the trip finger 28 is then spaced away or is disengaged from contact with the pin 29, permitting the spring 32 to again move the clutch plates 22 and 23 together in order that the (lI'lll blank may be rotated through 180 degrees as the head stock moves forward again to its initial position shown in Figs. 1 and 2. The cutting or grooving operation now takes place on the opposite side of the drill blank as the head stock makes its second forward movement. It being understood that the roller 69 starts again at the bottom of the let-off shoulder 7 3 of the cam wheel 70. This operation continues until the drill blank is formed with the second flute or groove. The gear wheel 89 and cam 70 have now made two complete revolutions to one of the gear 90, at which time, or period, the worm shaft 7 is disengaged by the pin 91 engaging the lever 92 allowing this shaft to fall whereby the machine comes to a standstill and is ready to have the finish i d 0 start the machine again the operator has only to lift the handle 95 which throws the gears 7 5 and 76 together.

It may be stated in the interest of clearness of operation, that as the drill blank 16 backs out of the bushing 15 (Fig. 9) on the return movement of the headstock 14 it is revolving at the same rate of revolution as it enters this bushing; it continues this rotary motion until the forward end of the blank is free from possible contact with the cutter,

When the head stock 14 reaches at which time the pawl 28 engages the pin 29 causing the clutch plates 22 and 23 to open and the rotation of the drill blank to cease. At the same time the blank revolving mechanism continues to rotate in a reverse direction through degrees at which point the clutch plates 22 and 23 reengage or pick up the drill blank. By the time the blank again reaches the bushing 15 and the cutter 4: it has been revolved in a clockwise direction through 180 degrees, or, in other words the opposite side of the drill blank is now presented to the-cutter on its opposite side having been revolved in a clockwise direction through 180 degrees from its position when it first entered the bushing.

lit is to be understood that the pitch or lead of the flutes can be varied by varying the radial position of the roller 42 and the angular position of the cam block 44 about its pivot 53. As the head stock moves forward the linger 28 snaps over the pin 29 permitted by .the spring 29 without operating the arm 27 which separates the clutch plates 22 and 23. On the return movement, however, of the head stock 14, when the same reaches a position in its travel to bring the finger 28 against the pin 29, the clutch plates 22 and 23 are automatically opened causing the reverse rotary motion of the drill blank to stop since the collar 24' is splined to the drill holding spindle, and, upon the separation of the plates 22 and 28 the drill blank is held stationary while the head stock completes the remainder of its rearward travel. After the first groove or flute has been cut in the drill blank 16, it is then backed out of the bushing 15 and away from the cutter 4 during the rearward travel of the head stock 14. Simultaneously with the rearward travel of the head stock the drill blank is rotated in the opposite direction from that during the cutting of the first flute or groove therein. This rearward motion ortravel of the head stock and blank continues until the forward end or point of the blank is free from any possible contact with the cutter 4. When this position of the blank is reached, the pawl 28 then engages the pin 29 to open or separate the clutch-plates 22 and 23 from each other preventing further contra clockwise rotation-of the blank. The drill-blank revolving mechanism including the gears 36, 25, 33 and 21 and the clutch plate 22 continues however, to operate, but the drill-blank can not be rotated since, as stated, the clutch plates 22 and 23 are now separated from each other. The plate 23 (see Fig. 6) is splined to the shaft 20 and when the clutch plates 22 are separated, rotation of this shaft ceases. 0n the return forward movement of the head stock, the clutch plates will rei ngage, being forced together by the spring 20. The pawl 28 idly snaps over the lllld llllti fluted.

pin 29 on the forward return movement and therefore permits the clutch to reengage. When the clutch plates reel gage the shaft 20 is again revolved in a clockwise direction, and by the time the point of the drill blank reaches the cutter at, the blank has been revolved so as to present its opposite side to the cutter to be @r, in other words, the blank has been rotated through 180 degrees in advance oil its previous position when the first flute is cut, since the point of the drill blank was withdrawn from the cutter i and bushing 15. The blank is now fluted or grooved on its opposite side, and after the second out has been made and the blank backed out of the bushing and away from the cutter the machine automatically stops when the tinished drill can be removed. The pitch of each llute is, therefore, 180 degrees.

it will be seen from this description that this machine automatically produces a tinished twist drill without the necessity of manual attention after the blank is inserted and the machine is started in operation.

l. The combination in a twistdrill form ing machine, of a base piece, a cutter rotatably supported thereon, means for clamping a drill blank in place, means for vary ing the angular relation both in a horizontal and vertical plane between the axis of the blank and the cutter, devices for automatically rotating the blank as the same is fed forward to the cutter, devices for antomatically maintaining the drill blank against rotation during a portion of its travel as the same is moved in a rearward direction away from the cutter and to cause the blank to present the opposite side or the blank to the cutter on its next forwa d movementtoward the cutter.

2. The combination in a machine for fluting or grooving twist-drill blanks, comprising a base piece, a cutter shaft, a cutter carried thereby, a head stock, a chuck car ried by the head stock for securing the drill blank, means to adjust the angular relation between the axis of the drill blank and the axis of the cutter shaft, a cam plate, operative mechanism between said plate and the chuck to automatically rotate the drill blank about its axis during the forward move ment of the head stock for varying the lead or pitch of the groove that is being cut in the blank, and means for automatically disconnecting said chuck and rotating means at a definite position during its travel in a reverse direction.

3. The combination in a machine for fluting or grooving twist drill blanks, comprising a base piece, a. cutter shaft, a cutter carried thereby, a head stock, a chuck carried by the head stock for securing the drill blank, means to adjust the angular relationblank about ship between the axis of the drill-blanl-1 and the axis of the cutteshalt, a cam block, operative mechanism between said block and the chuck to automatically rotate the drill its axis durins the forward movement of the head stock for varying the lead or pitch of the groove that is being cut in the blank, and means for automatically disconnecting said chuck and rotating means at the termination of the forward movement, automatic trip devices to cause the head stock to move at a greater rate o3? motion during the return movement than during the forward movement while the blank is being fluted.

l. A twist drill machine, comljirising a base member, a cutter supporting shalt mounted thereon, a plate movable on the bascunember for varying the angular rclation between the blank holding means and the cutter shalt, a worm shalt, bevel gear connections between the cutter sha d; and the worm shaft to permit the plate to move on the base piece, a table on which the drill blank supporting devices are carried, a lever connected to the table, means for lowering the table to vary the depth of cut of the flutes as the drill blank forming devices are moved forward toward the cutter, and means including a cam device on the lever for automatically moving the blank into a position that is free 'From the cutter at the termination of the cutting operation.

In a twist drill forming machine, the combination with a supporting base piece, of a plate pivotally mounted thereon, a cutter supporting sha'lt, a cutter secured thereto, a head stock with means for rotatably se curing the drill blank in place, means for moving the head stock toward, the cutter, means to automatically cause the drill blank to be rotated about its axis simultaneously with the forward movement of the head stock, means to automatically rotate the drill blank through 180 degrees during a definite part of the return movement of the head stock, and means to automatically disconnect the driving mechanism between the cutter and the head stock atthe termination of the grooving or iluting operations.

6. A twist drill machine, comprising in combination with a base piece, a plate movably secured thereto, a single cutter shaft having a cutter secured thereto, a movable head stock, a chuck for securing the drill blank and mounted on the plate, a table, an angular shaped cam plate secured thereto, a gear carried by the movable head stock, a threaded rod, a device on the gear having engagement with the cam block for moving the chuck, connecting mechanism between the gear and the spindle which drives the drill blank, a trip mechanism for automatically disengaging the connecting mechanism between the gear and the spindle at a fixed ill point in the return travel or the head stock,

said mechanism remaining in separated position during the balance of the return movement or" the head stock, said drill blank being automatically rotated so as to present the opposite side of the same to the cutter on its next forward movement, and means for automatically causing the connecting mechanism to reengage.

7. in a twist drill machine the combination with a base member, a plate on said member, a cam block pivotally secured thereto, a head stock, a link the pivotal center of which is offset from the center line thereof and attached to the base part of the machine, a second link connected to the opposite end of said link and to the head stock to cause the head stock to -move, a crank wheel for operating the links, a cutter shaft, a cutter secured thereto, means for varying the angular relation between the cutter and the axis of the drill blank, means to rotatably support the drill in the head stock, means for automatically disengaging and freeing the drill blank from the cutter at the end of each cutting operation, said means comprising a gear operated from the main shaft, a pivoted lever, a pin carried by the gear for engaging the lever, said lever having a shoulder portion which normally supports the worm shaft.

8. in a drill forming machine, the combination, a base-piece, a pivoted table secured thereto, means to permit movement of the table on the base piece, a lever having connection with the table, a spring actuated slide on the lever, a cam formed with a leton and a let-ofi' shoulder portion, a concentric surface, and an eccentric surface, a roller carried by the slide and engaging the cam, one end of the lever having an inclined slotted part engaged by the slide, whereby the end of the lever adjacent the cam will automatically lower the table as said cam is operated to bring the cutter completely away from the cutter blank at the termination of the cutting operation.

9.. in a drill forming machine, the com bination, means for automatically imparting a varying rotary motion to the drill lank as the same is fed toward the cutter to produce a flute or groove of varying pitch or lead, means for automatically stopping the rotary and forward motion of the blank at a predetermined position when a flute in the blank has been cut the desired length, means for automatically stopping the rotation of the drill blank during a portion of 1,2'2/ oon the rearward movement or the blank and while said drill rotating mechanism is being operated to index, or position the blank for flirting the same on its opposite side on its next forward movement toward the cutter, and means to cause the drill blank rotating devicesto be locked to the blank after said indexing operation.

10. In a drill-it'ormingmachine, the combination, with a traveling head-stock having a chuck to hold a drill blank for rotation, a cam device for automatically rotating the blank as the same and the head-stock is moved toward the cutter, means to hold the blank rotating means disengaged andv the blank stationary during a portion of the travel of the blank in a rearward direction away from the cutter, and until the headstock starts forward again toward the cutter and has reached a predetermined position in its travel toward the cutter at which position the blank has been indexed or positioned for cutting a flute on its opposite side, and means for reconnecting the blank rotating means to the chuck.

ll. lln a drill forming machine, the combination with a reciprocating head-stock, a cutter, means on the head-stock for rotatably holding a drill blank, devices to impart a rotary motion to the blank as the same is moved toward and away from the cutter, said devices serving to reverse the direction of rotation of the blank during the rearward travel of the blank away from the cutter for positioning said blank for cutting a groove on its opposite side during its next travel toward the cutter, means for automatically maintaining the blank rotating means disengaged during a portion of the travel of the head-stock both away from and toward the cutter, during which portion the blank remains stationary, and means for reconnecting the blank rotating" means to the chuck, said blank being positioned with relation to the cutter to have a groove cut on the opposite side of the same as the blank engages the cutter the second time 12. A drill iiuting machine, comprising, in combination with a base piece, a head stock slidably mounted thereon, means for reciprocating the head stock, a rotatable chuck to receive the drill blank, an adjustable and angular shaped cam block secured to the frame work, operative means between said block and the rotatable chuck for varying the pitch of the fluting, and a cutter for forming the flirting.

S. BICKFURD.

fltiitl 

